Rolling methods involving roll ultrasonic vibrations are known, which consist in that during common rolling of a plate ultrasonic vibrations are generated in rolls with the use of magnetostrictors attached to ends of the rolls (see: Severenko, V. P., Klubovich, V. V., Stepanenko, A. V. “Rolling and Drawing with Ultrasound”, Nauka I Tekhnika Publishing House, Minsk, 1970, p. 136-181).
When rolled with ultrasound, a treated material is subjected to vibrations of a variable amplitude, which is associated with a parallel arrangement of rolls relative to a plate and a significant length of a deformation area. And ultrasonic vibrations during rolling are only an auxiliary means for reducing friction forces and somewhat increasing plasticity of a treated material. During forging with the use of ultrasound vibrations are directed along the longitudinal axis of strikers, i.e., orthogonally to a plate. During ultrasonic forging a plate edge is directly deformed mainly due to an acoustic energy. Thus, processes occurring during deformation of a material treated by forging with ultrasound and by rolling with ultrasound are completely different, and, in contrast to forging, friction forces occurring during rolling with ultrasound are directed exactly along the longitudinal axis of a plate.
A method of producing a cutting tool blade is known, which comprises: forming a plate, deforming, by ultrasonic forging, a plate end arranged between the conical surfaces of strikers, while simultaneously moving the plate laterally relative to the strikers' axes for forming a wedge blade on the plate (SU No. 1720779).
According to the known method, a blank, while being deformed, is moved laterally to the applied static dam force, and a gap value between the strikers is maintained for the whole deformation cycle at the level of a double amplitude of ultrasonic vibrations.
An advantage of this method is the possibility of producing parts having cutting edge thickness from 1 to 3 microns and with a minimum burr or without it.
Disadvantages of the method are: complexity of the ultrasonic forging process due to the necessity of selecting a value of the static end force in the conditions of variable plate sizes and deviations of the plate movement true trajectory from that pre-set in a mechanism for moving a blank; the problem of maintaining a gap between the strikers during the whole deformation cycle; the necessity of using several lateral passes of a plate between the strikers for producing a cutting edge with a minimum thickness.
The principal disadvantage of the method, which, seemingly, enables to produce high-quality cutting edges having small metal grains and minimum thicknesses, as research works show, is the presence of a hidden defect in the form of a narrow slot-like micro cavity in the symmetry plane of a cutting edge.
In order to remove the said defect, another known technical solution proposes to round a plate edge (RU No. 2211742).
A disadvantage of the said method is the necessity of carrying out additional operations for producing a blank itself, which is provided with preliminary bevels by rolling, grinding, pressing in a die, or by preliminary ultrasonic forging of a plate end.
The principal disadvantage of the said method, which is inherent in the above ultrasonic forging methods also, is a small working surface area of strikers involved into deformation, that results in quick wear of the striker working surfaces and the necessity of stopping the whole process, repairing the tools and re-adjust the equipment.
A method of ultrasonic treatment of a part edge is known, which comprises ultrasonic forging deformation of an edge of a plate having a rectangular edge arranged between the wedge surfaces of strikers, wherein the plate is simultaneously moved laterally in relation to the longitudinal axes of the strikers, the latter being rotated about their longitudinal axes, and each of the strikers is provided with a hollow (groove) having a curvilinear generatrix on its wedge surface, the shape of the hollow corresponding to a pre-set profile of the part edge on the plate top and bottom (RU No. 2286227).
This method is used for making a cutting tool blade with a very sharp edge, in particular with a curvilinear generatrix of the groove, which generatrix can be described by the quadratic polynomial Y=±AX2±BX±C, where Y is the direction along the striker lateral axis, and X is the direction along the striker longitudinal axis.
The method enables to improve quality of a cutting edge, while maintaining its pre-set thickness, reduce the treatment time, improve roughness of the cutting edge surface, reduce the number of blank treatment operations in the process of ultrasonic forging, increase the service life of the tools used, make the control of the process and its automation better.
A disadvantage of this method is that it cannot be used for producing parts from plates having different thicknesses, e.g., when the plate thickness changes along the plate length or width. The method does not provide for making rounded edges having a variable radius, e.g., for parts having a complex shape, such as turbine vanes, etc. For example, at present turbine vanes are produced by precision grinding with the use of templates.
A device for ultrasonic treatment of a part edge is also known, which comprises strikers connected to ultrasonic vibration sources and arranged opposite to each other, and their working surfaces are made conical, the mechanism is made so as to provide movement of a plate with a rectangular edge between the striker working surfaces, laterally relative to their longitudinal axes, and is installed with the possibility of deforming the plate edge, an actuator is made with the possibility of rotating the strikers about their longitudinal axes, a hollow (groove) being made on each striker with a curvilinear generatrix on the striker wedge-like surface and having a shape corresponding to a pre-set profile of the part edge on the plate top and bottom (RU No. 2286227).
The said device is designed for producing cutting tool blades and has both the advantages and the disadvantages of the above method. The known device cannot produce a rounded edge of a blank having different thicknesses and a variable radius.
A striker is also known, which is included into the above device and which has a working surface made wedge-like and intended for deforming a plate edge by ultrasonic forging, a groove being made on the wedge-like working surface, which curvilinear generatrix corresponds in its shape to a pre-set profile of the part edge on the plate top and bottom (RU No. 2286227).
This striker enables to reduce wear of its working surface, improve the quality of the edge of a produced part, increase its service life and decrease a deforming force.
A disadvantage of this tool, i.e., a striker, is the impossibility of using it for rounding an edge of a blank having different thicknesses, e.g., for making a rounded end of a turbine vane without a burr, a buildup of a material or a cavity.